Acid Phosphatase-Rich Granules in Human Lymphocytes Induced by Phytohemagglutinin

Abstract

Human lymphocytes, cultured in the presence of phytohemagglutinin, undergo morphologic transformation and subsequent mitosis. Before mitosis (48 to 72 hours), a sharp increase in acid phosphatase activity occurs in cells stimulated with phytohemagglutinin. Histochemical examination of these cells demonstrates that innumerable granules containing acid phosphatase develop in the cytoplasm before mitosis. It is possible that enzymes present in granules which stain for acid phosphatase activity (lysosome-like) may play a role in phytohemagglutinin-stimulated cell division.